CN101406091A - Method and apparatus for re-establishing wireless communication sessions - Google Patents

Abstract

The present invention relates to maintaining or re-establishing a communication session in a wireless communication system. The present invention provides a method of rerouting a call between a user device and a third party device, the method comprising: establishing a call with the third party device using a first wireless connection between the user device and an access point; A quality parameter of the first wireless connection is monitored at the access point; and in response to determining that the quality parameter of the first wireless connection falls below a predetermined threshold, automatically sending a second wireless connection from a third party via the second wireless connection between the user device and the base station The device's call is redirected to the user.

Description

Method and apparatus for reestablishing a wireless communication session

technical field

The present invention relates to maintaining or re-establishing a communication session in a wireless communication system.

Background technique

With the development of access bandwidth and applications and the increase in popularity, the use of real-time communication based on packet switching via the Internet has increased. Examples include, for example, Internet telephony using Voice over Internet Protocol (VoIP), as well as popular applications such as Skype ^™ and video conferencing. However these types of calls are highly sensitive to delays or drop/drops of transmissions which can affect the quality and actual viability of the aforementioned services.

This problem is especially exacerbated when the above-mentioned techniques are employed over wireless access networks or links, for example on small portable devices such as mobile phones, personal digital assistants (PDAs) or even laptop computers. Wireless access technologies such as Wi-Fi (IEEE802.11) or Bluetooth can be used at home or in public places such as offices, cafes, airports, hotels, and shopping malls. This radio access technology has a number of features that are detrimental to packet-based real-time communications, including typically less bandwidth compared to the rest of the overall communication path, and noise and thus less reliable propagation resulting in delays, packet loss, and increase in speech. As electronic devices are increasingly provided with the capability of two or more wireless networks, there are several methods for rerouting calls via other networks when a call fails on one wireless network (for example, a portable handset moves out of range). mechanism. This problem also affects non-real-time communication services such as mail.

US2003/3134638 discloses a communication system with linked WLAN base stations and WWAN (Wireless Wide Area Network) base stations to which mobile phones or similar electronic devices can be connected. A mobile device can hand-over a call with a third party from WLAN to WWAN by first requesting a Temporary Local Number (TLDN) from the WLAN base station when it detects a degraded connection to the WLAN. When this connection fails, for example when the mobile phone moves out of range, the mobile phone uses the TLDN to request to place a call via the WWAN. Upon identification of the TLDN, the request is routed to the WLAN base station, which connects the incoming call with the third party.

US6804532 discloses a system in which a mobile device monitors the link quality of a wireless connection supporting a call and sends pre-routing information to a second wireless network in anticipation of the need for a handover, and then requests that the Calls are re-routed.

Contents of the invention

The present invention provides a method for maintaining or re-establishing communication traffic including a session with a third party or a VoIP call, which communication traffic has been established by using a wireless link or connection such as Bluetooth or Wi-Fi . An access point supporting a wireless link is configured to monitor the quality or connectivity of the wireless connection and, in response to the wireless connection becoming unreliable or a connection quality parameter (such as signal strength) dropping below a predetermined threshold, to send instructions Or request that the call be rerouted. The traffic can then be reconnected using another wireless link such as a GSM connection. The mobile device is set to automatically answer incoming calls from this other wireless link (eg GSM) and associate with a third party to continue the call without either party needing to redial. This means that if communication traffic (such as a VoIP call) can no longer be supported by the existing wireless link due to a user moving out of range or a change in the propagation environment, then use another wireless link that is stronger, has wider range, or has low interference The service or call is reconstructed on the road.

The use of a wireless connection access point to monitor the quality of the wireless connection and, if necessary, to generally control the initiation of handover to the wide area network (eg GSM) reduces the complexity of the mobile device and eliminates the need for the mobile device to have various links to the network side. A complex piece of software that interacts with the corresponding software of a network element. But this in turn typically requires an agreement between the network and the mobile device provider on an appropriate protocol to control the operation of the overall system, which in turn adds to the complexity of the mobile device. Furthermore, since there is no negotiation with the mobile required to perform a handover or re-routing, there is no indication that the mobile has moved completely out of range, so is not the same as requiring a mobile to effectuate a handover before attempting to issue a re-routing request. The system can make the wireless connection weaker than other methods. This is of particular advantage in wireless environments where the signal can fade rapidly causing problems for the mobile device attempting to effectuate a handover, or where the signal only fades temporarily without necessarily triggering a handover.

In one embodiment, the mobile phone initiates a VoIP call with a third party using a Bluetooth wireless link to an access point coupled to a VoIP server via the Internet. When the user moves out of range of the access point, the access point detects this and sends a request to the VoIP server to re-route the call onto the mobile phone using the mobile phone's GSM phone number. In response to identifying the appropriate third party identification code (eg, third party Calling Line ID (CLI)), the mobile phone receives the call and automatically accepts the call.

Typical real-time communication services may be packet-based calls such as VoIP or video calls, although other communication services may alternatively be provided, such as bursty data connections for maintaining email or web browsing connectivity.

In one aspect, a method for rerouting a call between a user device and a third party device is provided, and the method includes communicating with the third party using a first wireless connection, such as a Bluetooth connection between the user device and an access point. The device establishes a call, such as a VoIP call. During the duration of the call, the access point monitors a quality parameter of the first wireless connection, such as BER. The determination of whether a call is in progress may use control messages sent from the user device to the access point or by the access point monitoring SIP packets sent from or received by the user device, eg, indicating that a VoIP call is being established or is in progress. Then in response to determining that the quality parameter of the first wireless connection has dropped below a predetermined threshold (e.g., indicating that the user equipment has moved out of range of the access node employing the first wireless connection), the call is passed through the first wireless connection between the user equipment and the base station. Two wireless connections are automatically re-routed from the third party device to the user device. Re-routing of calls may be accomplished by a re-routing request sent by the access point upon determining that the user device has moved out of range. The re-routing request is sent to a network entity such as a VoIP server or media gateway, where the server application indicates the required re-routing of the call in response to instructions received from the access point.

In one embodiment, the rerouting uses a rerouting number or identification code associated with the user device and the second wireless connection, such as the user device GSM phone number. The re-routing number may be included in the re-routing request provided by the user device to the access point. It is mapped from the identification code of the identity.

Also provided is a system for rerouting a call between a user device and a third party device, the system comprising:

an access point connected to the user device using the first wireless link;

a network connected to the access point, a third party device, and a base station connected to the user device using the second wireless connection;

the access point is arranged to monitor a first radio connection quality parameter during a call between the user device and a third party over the first radio connection via said network;

The system is configured to automatically re-route calls from the third party to the user device via a second wireless connection between the user device and the base station in response to determining that a quality parameter of the first wireless connection has dropped below a predetermined threshold.

Also provided herein is a method for operating a user device, the method comprising connecting to an access point using a first wireless connection, connecting to a base station using a second wireless connection, placing a call with a third party device over the first wireless connection automatically receiving the call over the second wireless connection while automatically receiving the call over the second wireless connection in response to receiving a call setup request associated with the third party device over the second wireless connection.

Also provided herein is a method for a user to operate an access point, the method comprising connecting to a user device using a wireless connection, connecting to the network to provide a communication path between the user device and the network, monitoring a quality parameter of the wireless connection, as In response to detecting that the quality parameter drops below a threshold, a call rerouting request associated with the electronic device is sent to the network.

Description of drawings

Embodiments are now described, by way of example and without any limitation, with reference to the following drawings, in which:

Figure 1 depicts a high-level schematic block diagram of a communication system in accordance with an embodiment;

FIG. 2 depicts a flowchart of a method of operating an electronic device according to an embodiment;

Figure 3 depicts a flowchart of a method of operating an access point in accordance with an embodiment;

Figure 4 depicts a flowchart of a method of operating a call rerouting server in accordance with an embodiment; and

Figure 5 depicts a signaling diagram according to an embodiment.

Detailed ways

Figure 1 shows a wireless communication system that can be used to support real-time communication services, such as wireless telephony or video conferencing. The wireless communication system 100 includes a mobile phone 110 or other portable electronic device, an access point 120 , a VoIP server or network 130 , a PSTN network or voice server 140 , a third party device 150 , and a GSM network 160 . The electronic device 110 may be wirelessly connected to the access point 120 using short-range wireless technology or a link 116 such as Bluetooth or Wi-Fi. Access point 120 may be connected to VoIP server 130 using, for example, broadband Internet link 126 . PSTN network server 140 is connected to VoIP server 130 and GSM network server using known suitable links. The PSTN network 140 is connected to a third party device 150 such as a fixed line telephone using a PSTN link 143 .

The mobile electronic device 110 includes a mobile device client 113, which is usually implemented by a software module executed on a processor of the device, and operates according to the method of FIG. 2 . Similarly, the access point 120 includes an access point protocol station 122 that supports the communication link between the electronic device 110 and the VoIP server 130, such as transmitting VoIP over the Bluetooth wireless link 116 and the ASDL link 126 grouping. Access point client 124 operates in accordance with the method of FIG. 3 and includes the ability to monitor the quality of wireless link 116, in some embodiments having the ability to intercept or monitor traffic passing through access point protocol station 122 in order to identify certain types of packets. ability to group. In particular, access point client 124 may be configured to recognize and interpret Session Initiation Protocol (SIP) packets used to control VoIP calls. The re-routing server application 133 is typically associated with the VoIP server 130, but it may also be located at other parts of the network side (130, 140, 160) of the system 100. The rerouting server application 133 receives requests from the access point client 124 to reroute VoIP calls between the mobile device 110 and the third party device 150 through the GSM network 150 instead of through the access point 120 . A method of operating the server 133 will be described in detail with reference to FIG. 4 .

Figure 2 illustrates a method of operating mobile device 110 in accordance with one embodiment. The method (200) first establishes a VoIP call between the mobile device 110 and the third party 150 (205). A "short range" wireless link 116 to the access point 120 is first established (if the link does not already exist) and the VoIP call is then implemented using the access point's broadband Internet connection. VoIP call setup is accomplished through the use of SIP messages, which are sent to VoIP network 130 via wireless link 116 , as is well known to those skilled in the art. Typically, mobile device 110 sends a SIP INVITE message to VoIP server 130, which message includes a mobile device identification code such as its Skype phone number or calling line identity ( _CLI1 ), and usually also a third party phone number such as a third party phone number. The device's identification code (CLI ₃ ). This information is used by the VoIP server to call the third party 150, thereby completing the VoIP call. This will be described in detail with reference to FIG. 4 .

Once the VoIP call is established, the method optionally sends a control message to the access point client 124, instructing to perform a re-routing of the current call if the wireless connection 113 fails (210). The message may also include a re-routing number ( _CLI2 ) such as the GSM number of the mobile device. Alternatively, the access point can automatically detect VoIP call setup, such as by intercepting relevant SIP packets. This reduces the workload and complexity of the mobile device 110 . The method then sets up an auto-answer feature on the mobile device with the phone number ( _CLI3 ) or other suitable third-party identification code (210). The auto answer feature is included on most newer mobile phones and when set to automatically answer incoming GSM or other long range or cellular (eg CDMA, UMTS) wireless calls. However, the auto attendant is set to answer only incoming calls (CLI ₃ ) from third parties 150 or in response to a special identification code (CLI _special ), and not to any other calls with a different calling line identification code (CLI 3 ). Incoming calls are not answered. The user of the mobile device 110 uses the short-range WLAN or PAN (Personal Area Network) wireless link 116 to continue the VoIP call with the third party.

The mobile device 110 does not make a determination as to whether it is out of range of the access point 120 , this role is performed without the participation of the mobile device 110 . However, as a result of the mobile device moving out of range, the access point issues instructions to re-route the VoIP call to the mobile device 110 through the cellular GSM network 160 . Therefore in a next step (220), the method automatically answers an incoming GSM call on the GSM connection 163 from a GSM base station (generally shown as the GSM network 160), wherein the incoming call is associated with a third party Caller Line Identity (CLI ₃ ) Related. This identification code is typically sent as part of the known call setup process. The VoIP call then continues via the GSM or long-range wireless connection 163 with the mobile device 110 . The method then ends the VoIP call over the short-range wireless link, which is no longer supported (225). So while there may be brief pauses in the VoIP call, when the user of the mobile device moves out of range of the access point it does not need to redial the third party, but instead starts from the base station that provides the second wireless connection to the mobile device 110. This "replacement" call is automatically received at (160). Optionally, this may be accompanied by informing the user of the situation via a predetermined voice message.

Figure 3 illustrates a method of operating access point 120 in accordance with one embodiment. The method (300) first detects a VoIP call setup (305) from a mobile device. Since the SIP packet indicates the establishment of a VoIP call (the call may be established by the mobile device 110 or a third party device 150 calling the mobile device user), the above detection can be accomplished by detecting SIP packet traffic from the mobile device. Certain information can be recovered from these SIP packets, including the identity of the called third party ( _CLI3 ) and the identity of the mobile device ( _CLI1 ) (310). These identification codes can be used to reroute the call later. In an alternative configuration, a message may be sent from the mobile device 110 to the access point 120 (210) informing the mobile device that a VoIP call is being established, and the message may include the third party ( _CLI3 ) and/or rerouting number (CLI3) ₂ , such as a mobile device GSM phone number).

The method then monitors the short-range (eg, Bluetooth) wireless link 116 between the mobile device 110 and the access point 120 (215). This can be accomplished in a number of ways, such as by recording the signal strength or BER of what is known as link 116 . The method then checks whether the quality parameter or combination of quality parameters falls below a predetermined threshold, which indicates that the mobile device 110 has moved out of range (320). If not (320N), the method continues to monitor link quality. However, if the link quality indicates that the mobile station has moved out of range (320Y), the method sends a special rerouting order (325). This instruction is sent to the re-routing server application 133, which typically resides on the VoIP server 130, and is typically a SIP "path no longer valid" type message. The rerouting command can be configured to include the recovered third party's identity (CLI ₃ ), the GSM identity or rerouting number associated with the mobile device 110 (CLI ₂ ), or the original The identification code (CLI ₁ ) associated with the calling number or the called number of the mobile device for the VoIP call. The re-routing number (CLI ₂ ) may be initially communicated from the mobile device 110 to the access point (210), and either the access point or the re-routing call server 133 based on the mobile device's initial VoIP call number (CLI 2 ) using a suitable database. ₁ ) and mapped out. A mapping database 134 of subscriber identification code CLI1 to re-routing number or identification code CLI2 is indicated in FIG. 1 as being coupled to a re-routing server application 133 residing on a VoIP network or server 130 . These entities may however be distributed in any reasonable manner apparent to those skilled in the art. The re-routing message from the access point 120 to the re-routing server application 133 causes the VoIP call to be re-routed via the cellular or GSM network 160, as will be described in more detail with reference to FIG. 4 below. The method is then configured to close the wireless session or link 116 between the mobile device and the access point (330).

Figure 4 depicts a method (400) of operating a rerouting server application 133, which is typically integrated into the VoIP server 130 and which may form part of an updated VoIP routing protocol. Alternatively, the server application 133 may be associated with a PSTN 140 or cellular 160 network. Initially, a VoIP call is established by the VoIP network or server 130 using well-known SIP messages (405). SIP messages are used to set up each leg of the call between the mobile device 110 and the VoIP server 130 , and between the third party device 150 and the VoIP server 130 . Once the two legs are established, the VoIP server 130 connects the two legs and the call can be made. Once the VoIP call is established, the method waits for a re-routing message (410). The re-routing message may include the third party's identification code ( _CLI3 ), but alternatively the method may simply retrieve this information from the VoIP server which used this information to direct the initial call setup. The message may also include a rerouting number (CLI2). If the re-routing number was not included in the re-routing message, the method maps the mobile identity (CLI ₁ ) in the re-routing message or in the original VoIP call setup to the The user's associated landline, GSM number or other number such as a Skype username or number ( _CLI2 ) (415). This mapping may be contained in a database 134 associated with the rerouting server application 133, in which case the user will need to register their rerouting number with the rerouting service (133). Where the number used to reroute the call is provided by the access point, this may be programmed into the access point by the user.

The method then sends a voice message (420) to the third party, such as a pre-recorded message informing the third party that the current call is being redirected. The method then instructs the VoIP network to set up a new VoIP call with the rerouting message or the rerouting number ( _CLI2 ) in the mapping database (425). As previously discussed, in this embodiment, the rerouting number (CLI ₂ ) is associated with the GSM phone number of the electronic device 110 . The VoIP call setup is carried out in a standard way, the call setup message to the segment of the mobile device contains the third party identity ( _CLI3 ). Alternatively, a special application identifier (CLI _special ) associated with the application may be used. This call setup procedure causes the user's mobile device 110 to automatically answer incoming GSM calls as previously described. When a new VoIP call is established, the method connects (430) the newly established VoIP segment to the mobile device with the existing VoIP segment to the third party through the GSM base station so that the original VoIP call can be resumed. In an alternative arrangement, the method may delegate call setup and connection functions to another network entity, such as a PSTN network server (435), through suitable well-known control commands.

Figure 5 shows the signaling between the various entities of the system. User 501 instructs device client 113 to establish a VoIP call (505). Alternatively, a VoIP call could be established without a mobile device client, however depending on the system configuration this may prevent automatic re-routing if the user moves out of range. If a short-range wireless connection is not established with access point 120, the connection is made and the appropriate VoIP client of device 110 requests VoIP network 130 to establish a call to third party phone 150 (510). The VoIP network establishes a VoIP path between user device 110 and the VoIP network (515). The VoIP network 130 then sends a ring tone to a third party VoIP capable phone using a SIP message over, for example, a PSTN network (520). The ring tone reaches the third party user or called party (525), and when the third party user or called party answers the phone 150 (530), further SIP calls are exchanged between the third party phone 150 and the VoIP network 130. message to establish a VoIP path between the aforementioned well-known entities, (535). VoIP network 130 then connects these paths to form the call (540).

The access point 124 monitors the VoIP link (545) and sends a re-routing message to the re-routing server application 133 upon detection of the mobile device moving out of range (550). The rerouting server in turn commands the VoIP network to tear down the call between the VoIP network and client device 110 (555), and sends the voice message to the third party via the remaining call leg (560). The VoIP network then establishes a VoIP call or path to the mobile device GSM number ( _CLI2 ) (565), which is automatically answered by the mobile device client, and the VoIP call via the GSM connection is established (570). The VoIP network then connects the call with the mobile device 110 and the call with the third party 150 to establish an alternate route for the original VoIP call via the GSM network 160 (575).

So if a user moves out of range of an access point using a short-range wireless connection such as Bluetooth, the VoIP call is automatically re-routed to the mobile device via its own GSM or other cellular connection without requiring either party to redial the other side.

While embodiments have been described for rerouting VoIP calls from Bluetooth or Wi-Fi wireless connections to cellular (eg GSM, CDMA, UMTS) connections, this rerouting may involve performing rerouting announcements on the network side Any two networks, such as rerouting between Bluetooth and Wi-Fi networks. Similarly, communication sessions other than VoIP calls may be supported, such as mail connections, circuit switched calls, video calls.

Those skilled in the art will recognize that the apparatus and methods described above can be implemented as processor control code, for example on a carrier medium such as a hard disk, CD or DVD-ROM, on a programmable memory such as a read-only memory (firmware), or on a program such as Optical or electrical signal carrier on a data carrier. Various embodiments of the invention will be implemented on a DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). This code can thus contain conventional programming code or microcode, eg for building or controlling an ASIC or FPGA. The code may also include code for dynamically configuring reconfigurable devices, such as reprogrammable logic gate arrays. Similarly, the code may include code for a hardware description language such as Verilog ^™ or VHDL (Very High Speed Integrated Circuit Hardware Description Language). As understood by those skilled in the art, the code may be distributed among multiple connected intercommunicating components. Where appropriate, these embodiments may also be implemented using code running on a field (re)programmable analog array or similar device to configure the analog hardware.

Those skilled in the art should understand that, according to the above teachings, the above various embodiments and the specific features described for these embodiments can be freely combined with other embodiments or the specifically described features of these other embodiments. It will also be apparent to those skilled in the art that various changes and substitutions may be made to the specific examples described without departing from the spirit and scope of the appended claims.

Claims (13)

CLAIMS 1. A method for rerouting a call between a user device and a third party device, the method comprising: establishing a call with the third party device using a first wireless connection between the user device and an access point; monitoring a quality parameter of the first wireless connection at the access point; At the access point, in response to determining that the quality parameter of the first wireless connection has dropped below a predetermined threshold, connecting the Calls are automatically re-routed from the third party device to the user device. 2. The method of claim 1, wherein the automatic routing comprises the access point forwarding a re-routing message from the access point to a communication network entity instructing to re-route the call to the base station . 3. The method of claim 2, wherein the quality parameter monitoring is performed in response to the access point determining that a call has been established. 4. The method of claim 3, wherein the determination of call setup comprises identifying call setup packets communicated between the user device and the communication network entity. 5. A method according to any one of the preceding claims, further comprising mapping an identification code associated with the first wireless connection to an identification code associated with the second wireless connection to use the first wireless connection The two radio connection identifiers reroute the call. 6. A method as claimed in any one of the preceding claims, wherein the first wireless connection is a Bluetooth or Wi-Fi connection, the second wireless connection is a cellular wireless connection, and the call is a VoIP call. 7. An electronic device comprising: a transceiver for providing a first wireless connection with the access point; a second transceiver for providing a second wireless connection with the base station; a mobile device client configured to receive a call on said first wireless connection with a third party device automatically while receiving the call on said second wireless connection, as received on said second wireless connection In response to a call setup request associated with said third party device, the call is automatically accepted. 8. The device of claim 7, wherein the call setup request includes the third party device caller line identity (CLI). 9. The device of claim 7 or 8, wherein the mobile device client is further arranged to establish a call with the third party over the first wireless connection, the call being a VoIP call. 10. An access node, comprising: Transceivers for providing wireless connectivity to electronic devices; means for connecting to the network for providing a communication path between the electronic device and the network; means for monitoring a quality parameter of the wireless connection in response to determining that a call has been established between the electronic device and a third party device using the communication path; means for, in response to detecting that the quality parameter has dropped below a threshold, sending a request to the network to re-route a call associated with the electronic device. 11. The access point of claim 10, wherein the quality parameter comprises a bit error rate (BER) rating, and/or a signal strength indicator. 12. An access point as claimed in claim 10 or 11, wherein the determination that a call is established is achieved by detecting SIP packets on said communication path. 13. A carrying medium carrying processor code, wherein when the processor code is executed on the processor, the processor is made to execute the method according to any one of claims 1-6.

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